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author | Jacob Pan <jacob.jun.pan@linux.intel.com> | 2020-05-16 14:20:51 +0800 |
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committer | Joerg Roedel <jroedel@suse.de> | 2020-05-18 15:37:25 +0200 |
commit | 3375303e82877552f3b2b42309e8233fe715fd9f (patch) | |
tree | 73ae1b229a5e05e01b2754c8464504add1912cfc /drivers/iommu | |
parent | 24f27d32ab6b71dedcbbeeab8f9bdc143b539ac0 (diff) | |
download | linux-stable-3375303e82877552f3b2b42309e8233fe715fd9f.tar.gz linux-stable-3375303e82877552f3b2b42309e8233fe715fd9f.tar.bz2 linux-stable-3375303e82877552f3b2b42309e8233fe715fd9f.zip |
iommu/vt-d: Add custom allocator for IOASID
When VT-d driver runs in the guest, PASID allocation must be
performed via virtual command interface. This patch registers a
custom IOASID allocator which takes precedence over the default
XArray based allocator. The resulting IOASID allocation will always
come from the host. This ensures that PASID namespace is system-
wide.
Virtual command registers are used in the guest only, to prevent
vmexit cost, we cache the capability and store it during initialization.
Signed-off-by: Liu, Yi L <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200516062101.29541-9-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r-- | drivers/iommu/dmar.c | 1 | ||||
-rw-r--r-- | drivers/iommu/intel-iommu.c | 85 |
2 files changed, 86 insertions, 0 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 34ee8f28555f..66af08ad10fb 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -963,6 +963,7 @@ static int map_iommu(struct intel_iommu *iommu, u64 phys_addr) warn_invalid_dmar(phys_addr, " returns all ones"); goto unmap; } + iommu->vccap = dmar_readq(iommu->reg + DMAR_VCCAP_REG); /* the registers might be more than one page */ map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap), diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 627bb5093317..80d0bd561bdd 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1726,6 +1726,9 @@ static void free_dmar_iommu(struct intel_iommu *iommu) if (ecap_prs(iommu->ecap)) intel_svm_finish_prq(iommu); } + if (ecap_vcs(iommu->ecap) && vccap_pasid(iommu->vccap)) + ioasid_unregister_allocator(&iommu->pasid_allocator); + #endif } @@ -3038,6 +3041,85 @@ out_unmap: return ret; } +#ifdef CONFIG_INTEL_IOMMU_SVM +static ioasid_t intel_vcmd_ioasid_alloc(ioasid_t min, ioasid_t max, void *data) +{ + struct intel_iommu *iommu = data; + ioasid_t ioasid; + + if (!iommu) + return INVALID_IOASID; + /* + * VT-d virtual command interface always uses the full 20 bit + * PASID range. Host can partition guest PASID range based on + * policies but it is out of guest's control. + */ + if (min < PASID_MIN || max > intel_pasid_max_id) + return INVALID_IOASID; + + if (vcmd_alloc_pasid(iommu, &ioasid)) + return INVALID_IOASID; + + return ioasid; +} + +static void intel_vcmd_ioasid_free(ioasid_t ioasid, void *data) +{ + struct intel_iommu *iommu = data; + + if (!iommu) + return; + /* + * Sanity check the ioasid owner is done at upper layer, e.g. VFIO + * We can only free the PASID when all the devices are unbound. + */ + if (ioasid_find(NULL, ioasid, NULL)) { + pr_alert("Cannot free active IOASID %d\n", ioasid); + return; + } + vcmd_free_pasid(iommu, ioasid); +} + +static void register_pasid_allocator(struct intel_iommu *iommu) +{ + /* + * If we are running in the host, no need for custom allocator + * in that PASIDs are allocated from the host system-wide. + */ + if (!cap_caching_mode(iommu->cap)) + return; + + if (!sm_supported(iommu)) { + pr_warn("VT-d Scalable Mode not enabled, no PASID allocation\n"); + return; + } + + /* + * Register a custom PASID allocator if we are running in a guest, + * guest PASID must be obtained via virtual command interface. + * There can be multiple vIOMMUs in each guest but only one allocator + * is active. All vIOMMU allocators will eventually be calling the same + * host allocator. + */ + if (!ecap_vcs(iommu->ecap) || !vccap_pasid(iommu->vccap)) + return; + + pr_info("Register custom PASID allocator\n"); + iommu->pasid_allocator.alloc = intel_vcmd_ioasid_alloc; + iommu->pasid_allocator.free = intel_vcmd_ioasid_free; + iommu->pasid_allocator.pdata = (void *)iommu; + if (ioasid_register_allocator(&iommu->pasid_allocator)) { + pr_warn("Custom PASID allocator failed, scalable mode disabled\n"); + /* + * Disable scalable mode on this IOMMU if there + * is no custom allocator. Mixing SM capable vIOMMU + * and non-SM vIOMMU are not supported. + */ + intel_iommu_sm = 0; + } +} +#endif + static int __init init_dmars(void) { struct dmar_drhd_unit *drhd; @@ -3155,6 +3237,9 @@ static int __init init_dmars(void) */ for_each_active_iommu(iommu, drhd) { iommu_flush_write_buffer(iommu); +#ifdef CONFIG_INTEL_IOMMU_SVM + register_pasid_allocator(iommu); +#endif iommu_set_root_entry(iommu); iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL); iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH); |